1. Field of the Invention
The present invention relates to a method and chamber for separating granulocytes from whole blood. More specifically, the present invention relates to a specific configuration of a chamber and the orientation of the chamber for providing enhanced separation of granulocytes from whole blood while whole blood is undergoing centrifugal force within the chamber.
2. Description of the Prior Art
Heretofore methods and apparatus for taking whole blood from a source, such as a donor, and centrifuging the blood within a separation chamber for separating the whole blood into components thereof and then collecting one or more components of the blood, followed by recombining the remaining components and returning the recombined blood to the donor, have been proposed. Examples of such methods and apparatus are disclosed in the following U.S. Patents:
______________________________________ U.S. PAT. NO. PATENTEE ______________________________________ 4,146,172 Cullis et al. 4,185,629 Cullis et al. 4,187,979 Cullis et al. ______________________________________
U.S. Pat. No. 4,146,172 is directed to: Centrifugal Liquid Processing System wherein there is disclosed and claimed a particular configuration for a blood separation chamber and for platens with mating cavities therein within which a flexible plastic receptacle is received so as to form a blood separation chamber therein having the configuration of the mating cavities.
U.S. Pat. No. 4,185,629 is directed to: Method and Apparatus for Processing Blood and discloses a method and apparatus for separating whole blood into its components and a separation chamber of the type disclosed and claimed in U.S. Pat. No. 4,146,172.
In the blood separation chamber disclosed in U.S. Pat. Nos. 4,146,172 and 4,185,629 whole blood is introduced into the chamber at the bottom thereof, red blood cells are removed from opposite top edges of the chamber which are disposed at approximately the same radius from the axis of rotation of a centrifuge device in which the chamber is mounted, and platelet rich plasma is removed from the top center portion of the chamber which is located at a shorter radius from the axis of rotation of the centrifuge device.
U.S. Pat. No. 4,187,979 directed to: Method and System for Fractionating a Quantity of Blood into the Components Thereof discloses a method and system for separating whole blood into red blood cells, white blood cells, platelets and plasma. The method and system also provide collection chambers, either within the centrifuge device or outside the centrifuge device, for collecting white blood cells, platelets and plasma. In this device, a generally square separation chamber positioned in the centrifuge device in a diamond position is disclosed with whole blood being introduced into one side corner of the chamber and red blood cells being withdrawn from the other side corner of the chamber. Plasma with white blood cells and platelets is withdrawn from the top corner of the chamber and is circulated through a white blood cell separation chamber and then through a platelet separation chamber within the centrifuge device. Then, the plasma withdrawn from the platelet separation chamber is returned to the bottom corner of the separation chamber so that it is passed upwardly through the square separation chamber thereby to elute white blood cells and platelets from the whole blood and red blood cells flowing across the blood separation chamber.
The apparatus disclosed in each of the three patents identified above utilize an optical spill detector or sensor which senses the optical density of the plasma being withdrawn from the whole blood separation chamber so that the amount of red blood cells being withdrawn with the plasma can be monitored and controlled in a manner as disclosed in these patents. Also, a specific optical detector for use in the apparatus disclosed in these three patents is disclosed and claimed in U.S. Pat. No. 4,227,814.
The disclosures of U.S. Pat. Nos. 4,146,172; 4,185,629; 4,187,979; and 4,227,814 are incorporated herein by reference.
In the separation of whole blood into the components thereof as taught in the patents identified above, whole blood is pumped into the separation chamber undergoing centrifugation at a given volumetric rate and plasma containing platelets and/or white blood cells is withdrawn at another volumetric rate. The rate of withdrawal of plasma is increased until the optical density thereof exceeds a certain level indicating that a certain quantity of red blood cells is being withdrawn with the plasma. Then the pump for withdrawing plasma is reversed to return a predetermined amount of plasma with red blood cells mixed therein to the separation chamber, the volumetric displacement of the plasma pump is reduced and reversed to its original pumping direction and the plasma pump re-energized to repeat this procedure until a certain amount of whole blood has been processed. In this way, plasma rich with platelets and/or white blood cells is withdrawn from the blood separation chamber with little or minimal contamination thereof with red blood cells. However, because of the nature of whole blood, the granulocyte cells of the white blood cells were not efficiently separated from the red blood cells.
Separation of white blood cells, particularly granulocytes, from the whole blood was improved by passing whole blood/red blood cells through a blood separation chamber undergoing centrifugation from one side thereof to the other side thereof while at the same time passing plasma through the separation chamber from the bottom thereof to the top thereof so that the plasma served to elute white blood cells, such as granulocytes, from the red blood cells. A method and system providing for such cross-flows of whole blood/red blood cells and plasma in a blood separation chamber is disclosed in U.S. Pat. No. 4,187,979 referred to above.
As will be described in greater detail hereinafter, the method and separation chamber of the present invention provide for more efficient separation of white blood cells, particularly granulocytes, from whole blood than was obtained from the previous methods, apparatus and systems. The better separation of granulocytes from whole blood is achieved, in accordance with the teachings of the present invention, by the particular configuration and orientation of the blood separation chamber.
Also according to the teachings of the present invention, the blood separation chamber is formed from two mating cavities disposed respectively in inner and outer platens which are releasably received in a platen, holder and latch assembly for securing the platens in place in a centrifuge device. The particular platen, holder and latch assembly is of the type disclosed in copending application Ser. No. 102,747 filed on Dec. 12, 1979 for: Platen, Holder and Latch Assembly for Securing Platens in Place within a Centrifuge Device, now U.S. Pat. No. 4,266,717, the disclosure of which is incorporated herein by reference.
Further as will be described in greater detail hereinafter, the separation chamber of the present invention is configured and arranged so that whole blood enters the chamber from one side thereof between the bottom and top of the chamber and in a way so that red blood cells are directed downwardly and outwardly to a bottom corner of the chamber and plasma with white blood cells and platelets therein is directed upwardly out a top center exit port from the chamber.